3.2 MU-M INFRARED RESONANT-CAVITY LIGHT-EMITTING DIODE

A CdHgTe resonant cavity light emitting diode is proposed as a new infrared emitter. The device consists of a bottom Bragg reflector of 86% reflectivity, a half-wavelength cavity, n doped at the beginning (10(18) cm(-3)) and p doped at the end (10(18) cm(-3)), containing an active layer at the antinode position, and a top gold mirror of 95% reflectivity which also serves as an Ohmic contact. The emission spectrum shows a narrow peak of 8 meV full width at half-maximum (FWHM) at 300 K, which is much less than the inhomogeneous linewidth of CdHgTe quantum wells (QWs). This electroluminescent peak matches very well the cavity resonance wavelength and FWHM, as given by transmission measurements of the unbiased cavity. The directivity is also improved by the cavity effect. Thus, we have demonstrated that even a relatively low Q microcavity can greatly enhance the characteristics of an infrared emitter in the 2-5 mu m range. (C) 1995 American Institute of Physics.